Friedrich PTAC - R410A service manual External Overload, Single Phase Resistance Test, Ground Test

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WARNING

BURN HAZARD

Certain unit components operate at temperatures hot enough to cause burns.

Proper safety procedures must be followed, and proper protective clothing must be worn.

Failure to follow this warning could result in moderate to serious injury.

External Overload

With power off, remove the leads from compressor termi- nals. If the compressor is hot, allow the overload to cool before starting check. Using an ohmmeter, test continu- ity across the terminals of the external overload. If you do not have continuity; this indicates that the overload is open and must be replaced.

Single Phase Resistance Test

WARNING

ELECTRIC SHOCK HAZARD

Turn off electric power before service or installation. Extreme care must be used, if it becomes necessary to work on equipment with power applied.

Failure to do so could result in serious injury or death.

Remove the leads from the compressor terminals and set the ohmmeter on the lowest scale (R x 1).

Touch the leads of the ohmmeter from terminals common to start (“C” to “S”). Next, touch the leads of the ohmmeter from terminals common to run (“C” to “R”).

Add values “C” to “S” and “C” to “R” together and check resistance from start to run terminals (“S” to “R”). Resistance “S” to “R” should equal the total of “C” to “S” and “C” to “R.”

In a single phase PSC compressor motor, the highest value will be from the start to the run connections (“S” to “R”). The next highest resistance is from the start to the common connections (“S” to “C”). The lowest resistance is from the run to common. (“C” to “R”) Before replacing a compressor, check to be sure it is defective.

GROUND TEST

Use an ohmmeter set on its highest scale. Touch one lead to the compressor body (clean point of contact as a good connection is a must) and the other probe in turn to each compressor terminal. If a reading is obtained the compressor is grounded and must be replaced.

Check the complete electrical system to the compressor and compressor internal electrical system, check to be certain that compressor is not out on internal overload.

Complete evaluation of the system must be made whenever you suspect the compressor is defective. If the compressor has been operating for sometime, a careful examination must be made to determine why the compressor failed.

Many compressor failures are caused by the following conditions:

1.Improper air fl ow over the evaporator.

2.Overcharged refrigerant system causing liquid to be returned to the compressor.

3.Restricted refrigerant system.

4.Lack of lubrication.

5.Liquid refrigerant returning to compressor causing oil to be washed out of bearings.

6.Noncondensables such as air and moisture in the system. Moisture is extremely destructive to a refrigerant system.

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Contents Ptac R410A Models Technical Support Contact Information Table of Contents Your safety and the safety of others are very important Important Safety InformationPersonal Injury or Death Hazards Mechanical Hazards IntroductionGeneral Product Features Digital Packaged Terminal Air Conditioners & Heat Pumps Component Identification Accessories Pxfta Unit Identification Chassis Specifications Cooling & Heating Performance PDE 265V Extended Cooling Performance Electric Heat Data Power Cord Information 230/208V Models only Electrical Rating TablesElectric Shock Hazard Electrical Wiring for 265 Volt Models To Chassis Junction Remote Control Thermostat Installation Desk Control Terminals Digital Temperature Friedrich Digital Control Features+*&-.4-*2+4 #$%&#*%&+,-*&./0#&1!0*$# DIP SwitchDigital Control Diagnostics Fan can’t run or the fan speed is too slow Malfunction AnalysisKeep the air tightness well. Try not to use the electic Supply voltage is abnormal Capacitor Connections Components TestingCapacitors Capacitor Check with Capacitor AnalyzerDrain PAN Valve Heater Elements and Limit SWITCHES’ SpecificationsRefrigeration Sequence of Operation Risk of Electric Shock 410A Sealed Refrigeration System RepairsEquipment Required Equipment Must be CapableFreeze Hazard Method Of Charging / RepairsUndercharged Refrigerant Systems Burn HazardRestricted Refrigerant System Overcharged Refrigerant SystemsCapillary Tube Systems Hermetic Components CheckMetering Device Check ValveTesting the Coil Reversing Valve DESCRIPTION/OPERATIONChecking the Reversing Valve Procedure For Changing Reversing Valve Touch Test in Heating/Cooling CycleFire Hazard Compressor Checks Single Phase Resistance Test External OverloadGround Test Compressor Replacement Recommended procedure for compressor replacementHigh Temperatures Electrical Shock Hazard Routine MaintenanceTroubleshooting Chart Heating Troubleshooting Chart CoolingElectrical Troubleshooting Chart Heat Pump System Cools When Heating is DesiredYES Electronic Control Board Electronic Control Board Component ID Wiring DiagramRT6 5558+131!8 Resistance Table for Air Indoor Temperature Sensor Temp Resistance Friedrich Packaged Terminal AIR Conditioners and Heat Pumps Ptac Exploded View Ptac Parts List PDE Models Ptac Parts List PDH Models Friedrich AIR Conditioning CO